Add Google AI file summarization package (#2455)

- [x] Create new directory pkg/aiusechat/google
- [x] Implement SummarizeFile function with:
  - Context parameter for timeout
  - File validation (images, PDFs, text files only)
  - Use gemini-2.5-flash-lite model
  - Configurable API URL and prompt as constants
  - Return (string, usage, error)
- [x] Define Google-specific usage struct
- [x] Test the implementation (all tests pass)
- [x] Verify with existing linting and build
- [x] Run CodeQL security check (no issues found)
- [x] Revert unintended tsunami demo dependency changes

## Summary

Successfully implemented a new Google AI package at
`pkg/aiusechat/google` with:

1. **SummarizeFile function** - A simple request-response API (not
streaming, not SSE)
   - Takes context for timeout
   - Validates file types (images, PDFs, text only) 
   - Enforces file size limits matching wshcmd-ai.go
   - Uses gemini-2.5-flash-lite model
   - Returns (summary string, usage stats, error)

2. **GoogleUsage struct** - Tracks token consumption:
   - PromptTokenCount
   - CachedContentTokenCount  
   - CandidatesTokenCount
   - TotalTokenCount

3. **Configurable constants**:
   - GoogleAPIURL (for reference)
   - SummarizePrompt (customizable prompt)
   - SummarizeModel (gemini-2.5-flash-lite)

4. **Comprehensive tests** - 41.7% coverage with all tests passing
5. **Security verified** - No CodeQL alerts
6. **Package documentation** - doc.go with usage examples

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: sawka <2722291+sawka@users.noreply.github.com>

Author: Copilot

cmd/testsummarize/main-testsummarize.go

@@ -0,0 +1,104 @@
+// Copyright 2025, Command Line Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/wavetermdev/waveterm/pkg/aiusechat/google"
+)
+
+func printUsage() {
+	fmt.Println("Usage: go run main-testsummarize.go [--help] [--mode MODE] <filename>")
+	fmt.Println("Examples:")
+	fmt.Println("  go run main-testsummarize.go README.md")
+	fmt.Println("  go run main-testsummarize.go --mode useful /path/to/image.png")
+	fmt.Println("  go run main-testsummarize.go -m publiccode document.pdf")
+	fmt.Println("")
+	fmt.Println("Supported file types:")
+	fmt.Println("  - Text files (up to 200KB)")
+	fmt.Println("  - Images (up to 7MB)")
+	fmt.Println("  - PDFs (up to 5MB)")
+	fmt.Println("")
+	fmt.Println("Flags:")
+	fmt.Println("  --mode, -m  Summarization mode (default: quick)")
+	fmt.Println("              Options: quick, useful, publiccode, htmlcontent, htmlfull")
+	fmt.Println("")
+	fmt.Println("Environment variables:")
+	fmt.Println("  GOOGLE_APIKEY (required)")
+}
+
+func main() {
+	var showHelp bool
+	var mode string
+	flag.BoolVar(&showHelp, "help", false, "Show usage information")
+	flag.StringVar(&mode, "mode", "quick", "Summarization mode")
+	flag.StringVar(&mode, "m", "quick", "Summarization mode (shorthand)")
+	flag.Parse()
+
+	if showHelp {
+		printUsage()
+		os.Exit(0)
+	}
+
+	apiKey := os.Getenv("GOOGLE_APIKEY")
+	if apiKey == "" {
+		fmt.Println("Error: GOOGLE_APIKEY environment variable not set")
+		printUsage()
+		os.Exit(1)
+	}
+
+	args := flag.Args()
+	if len(args) == 0 {
+		fmt.Println("Error: filename required")
+		printUsage()
+		os.Exit(1)
+	}
+
+	filename := args[0]
+
+	// Check if file exists
+	if _, err := os.Stat(filename); os.IsNotExist(err) {
+		fmt.Printf("Error: file '%s' does not exist\n", filename)
+		os.Exit(1)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+
+	fmt.Printf("Summarizing file: %s\n", filename)
+	fmt.Printf("Model: %s\n", google.SummarizeModel)
+	fmt.Printf("Mode: %s\n", mode)
+
+	startTime := time.Now()
+	summary, usage, err := google.SummarizeFile(ctx, filename, google.SummarizeOpts{
+		APIKey: apiKey,
+		Mode:   mode,
+	})
+	latency := time.Since(startTime)
+
+	fmt.Printf("Latency: %d ms\n", latency.Milliseconds())
+	fmt.Println("===")
+	if err != nil {
+		fmt.Printf("Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	fmt.Println("\nSummary:")
+	fmt.Println("---")
+	fmt.Println(summary)
+	fmt.Println("---")
+
+	if usage != nil {
+		fmt.Println("\nUsage Statistics:")
+		fmt.Printf("  Prompt tokens: %d\n", usage.PromptTokenCount)
+		fmt.Printf("  Cached tokens: %d\n", usage.CachedContentTokenCount)
+		fmt.Printf("  Response tokens: %d\n", usage.CandidatesTokenCount)
+		fmt.Printf("  Total tokens: %d\n", usage.TotalTokenCount)
+	}
+}

pkg/aiusechat/google/doc.go

@@ -0,0 +1,41 @@
+// Copyright 2025, Command Line Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+// Package google provides Google Generative AI integration for WaveTerm.
+//
+// This package implements file summarization using Google's Gemini models.
+// Unlike other AI provider implementations in the aiusechat package, this
+// package does NOT implement full SSE streaming. It uses a simple
+// request-response API for file summarization.
+//
+// # Supported File Types
+//
+// The package supports the same file types as defined in wshcmd-ai.go:
+//   - Images (PNG, JPEG, etc.): up to 7MB
+//   - PDFs: up to 5MB
+//   - Text files: up to 200KB
+//
+// Binary files are rejected unless they are recognized as images or PDFs.
+//
+// # Usage
+//
+// To summarize a file:
+//
+//	ctx := context.Background()
+//	summary, usage, err := google.SummarizeFile(ctx, "/path/to/file.txt", google.SummarizeOpts{
+//		APIKey: "YOUR_API_KEY",
+//		Mode:   google.ModeQuickSummary,
+//	})
+//	if err != nil {
+//	    log.Fatal(err)
+//	}
+//	fmt.Println("Summary:", summary)
+//	fmt.Printf("Tokens used: %d\n", usage.TotalTokenCount)
+//
+// # Configuration
+//
+// The summarization behavior can be customized by modifying the constants:
+//   - SummarizeModel: The Gemini model to use (default: "gemini-2.5-flash-lite")
+//   - SummarizePrompt: The prompt sent to the model
+//   - GoogleAPIURL: The base URL for the API (for reference, not currently used by the SDK)
+package google